Switching audio clients to using RestartableAudioRendererSink interface as a sink.

content/renderer/media/restartable_audio_output_device_factory.h

+// Copyright (c) 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_RENDERER_MEDIA_RESTARTABLE_AUDIO_OUTPUT_DEVICE_FACTORY_H_
+#define CONTENT_RENDERER_MEDIA_RESTARTABLE_AUDIO_OUTPUT_DEVICE_FACTORY_H_
+
+#include <string>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "content/common/content_export.h"
+#include "media/audio/audio_parameters.h"
+
+namespace media {
+class RestartableAudioOutputDevice;
+}
+
+namespace url {
+class Origin;
+}
+
+namespace content {
+
+// A factory for creating RestartableAudioOutputDevice.
+// There is a global factory function that can be installed for the purposes of
+// testing to provide specialized implementations.
+class CONTENT_EXPORT RestartableAudioOutputDeviceFactory {
+ public:
+  enum SourceType {
+    kSourceHighLatency = 0,
+    kSourceWebRTC,
+    kSourceLocalUserMedia,
+    kSourceWebAudio,
+    kSourceLast = kSourceWebAudio  // Only used for validation of format.
+  };
+
+  // Creates an RestartableAudioOutputDevice.
+  // |render_frame_id| refers to the RenderFrame containing the entity
+  // producing the audio. If |session_id| is nonzero, it is used by the browser
+  // to select the correct input device ID and its associated output device, if
+  // it exists. If |session_id| is zero, |device_id| and |security_origin|
+  // identify the output device to use.
+  // If |session_id| is zero and |device_id| and |security_origin| are empty,
+  // the default output device will be selected.
+  static scoped_refptr<media::RestartableAudioOutputDevice> NewOutputDevice(
+      SourceType source_type,
+      int render_frame_id,
+      int session_id,
+      const std::string& device_id,
+      const url::Origin& security_origin);
+
+  // TODO(olka): find a better home for this function.

[o1ka, 2016/02/05 16:04:23]

Could you suggest a better place for it? A dedicated file seems to be an
overkill, doesn't it?

+  // A helper to get output HW parameters in the absence of AudioOutputDevice.
+  static media::AudioParameters GetOutputHWParams(
+      int render_frame_id,
+      int session_id,
+      const std::string& device_id,
+      const url::Origin& security_origin);
+
+ protected:
+  RestartableAudioOutputDeviceFactory();
+  virtual ~RestartableAudioOutputDeviceFactory();
+
+  // You can derive from this class and specify an implementation for this
+  // function to provide alternate restartable audio output device
+  // implementations. If the return value of this function is NULL, we fall back
+  // on the default implementation.
+  virtual media::RestartableAudioOutputDevice* CreateOutputDevice(
+      SourceType source_type,
+      int render_frame_id,
+      int sesssion_id,
+      const std::string& device_id,
+      const url::Origin& security_origin) = 0;
+
+ private:
+  // The current globally registered factory. This is NULL when we should
+  // create the default AudioRendererSinks.
+  static RestartableAudioOutputDeviceFactory* factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(RestartableAudioOutputDeviceFactory);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_MEDIA_RESTARTABLE_AUDIO_OUTPUT_DEVICE_FACTORY_H_